In an announcement, Bronin, a Democrat who previously worked as chief legal counsel to Gov. Dannel P. Malloy, pointed to his experience so far running the city.

"After tackling Hartford's historic fiscal crisis over the past two years, I know what it means to face hard problems head-on and honestly, and not shy away from tough choices," he said.

The mayor said Connecticut needs to "defend the progressive values that are under attack across our country and especially by Donald Trump" and that it needs "a shared vision for restoring economic growth and opportunity."

Bronin's committee treasurer is Sebastian Lombardi, an attorney with Day Pitney, according to the State Elections Enforcement Commission.

Democratic Middletown Mayor Dan Drew has declared he is running for governor, while a number of other Democrats have formed exploratory committees, including Jonathan Harris, Joe Ganim and Dita Bhargava. Declared Republicans include Prasad Srinivasan and Tim Herbst. Mark Boughton and Toni Boucher have formed exploratory committees.